Laundry treating appliance and method of operation

ABSTRACT

A method of operating a laundry treating appliance having a drum, and an air conduit fluidly coupled to the drum, with a heat source associated with the air conduit, includes moving air through an air conduit to the drum; heating the moving air by operating the heat source; and introducing atomized liquid into the air conduit upstream of the heat source.

BACKGROUND OF THE INVENTION

Contemporary laundry treating appliances, such as clothes dryers, may beprovided with a treating chamber for receiving a laundry load fortreatment, such as drying, and a heating element for heating the air totreat the laundry load. Contemporary laundry treating appliances caninclude clothes dryers that utilize a heat source, to heat air forcedthrough the clothes dryer to dry a load of washed clothes. Contemporarylaundry treating appliances, such as clothes dryers, may have aconfiguration based on a rotating drum that defines a treating chamberin which laundry items are placed for treating according to a cycle ofoperation. A controller may be operably connected with the air conduitand may have various components of the laundry treating appliance toexecute the cycle of operation. The cycle of operation may be selectedmanually by the user or automatically based on one or more conditionsdetermined by the controller.

SUMMARY

One aspect of the invention is a method of operating a laundry treatingappliance comprised of a drum, and an air conduit fluidly coupled to thedrum. A heat source is associated with the air conduit. The methodcomprises moving the air through the air conduit, heating the air byoperating the heat source, and introducing atomized liquid into the airconduit upstream of the heat source wherein the heat from the heatsource heats the air and atomized liquid prior to the introduction ofthe air containing atomized liquid into the drum.

Another aspect of the invention is a laundry treating appliancecomprising a drum defining a treating chamber that is fluidly coupled toan air conduit. A blower forces air through the air conduit. A heatsource is associated with the air conduit and an atomizer fluidlycoupled to the air conduit upstream of the heat source wherein theatomizer is configured to introduce atomized liquid into the airconduit.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:

FIG. 1 is a schematic view of a heat pump clothes dryer according to oneembodiment of the invention.

FIG. 2 is a schematic view of relevant components of a heat pump systemof FIG. 1.

FIG. 3 is a schematic view of a controller of the heat pump clothesdryer in FIG. 1.

FIG. 4 is a flow chart illustrating a method according to an embodimentof the invention.

DESCRIPTION OF EMBODIMENTS OF THE INVENTION

FIG. 1 is a schematic view of a laundry treating appliance in the formof a heat pump clothes dryer 10 according to an embodiment of theinvention. The clothes dryer 10 of the illustrated embodiment mayinclude a cabinet 12 defined by a front wall 18, a rear wall 20, a pairof side walls 22 and a supporting top wall 24. A control panel or userinterface 16 may include one or more knobs, switches, displays, and thelike for communicating with the user, such as to receive input andprovide output. A controller 14 may receive input from a user through auser interface 16 for selecting a cycle of operation and controlling theoperation of the heat pump clothes dryer 10 to implement the selectedcycle of operation.

A rotatable drum 28 may be disposed within the interior of the cabinet12 to define a treating chamber 34 for treating laundry 36.

An air recirculation loop 38 is fluidly coupled to and recirculates airthrough the treating chamber 34. A recirculation loop air conduit 44connects the drum 28 to a heat pump system 100 (FIG. 2). The heat pumpsystem 100 contains a heat exchanger comprising an evaporator 105 and acondenser 110. Under the evaporator 105 a condensate reservoir 62collects condensed water from the recirculating air. A lint trap 37 maybe provided at an inlet to the recirculation loop air conduit 44 fromthe treating chamber 34.

FIG. 2 is a schematic view of relevant components of a heat pump system100 of a heat pump clothes dryer according to an embodiment of theinvention. The heat pump system 100 involves a refrigerant loop 114 thatwith its phase variation, transfers heat to and from the recirculatingair in the recirculation loop 38 by way of the heat exchanger. Anexpansion tube 116, evaporator 105, condenser 110, and compressor 112comprise the refrigerant loop 114 to affect phase variation and transferheat in the heat exchanger of the recirculation loop. A blower 58 may belocated within the air recirculation loop 38 and operably coupled to andcontrolled by the controller 14. For example, blower 38 may be locateddownstream of the drum 28 and upstream of the evaporator 105. In anotherexample, blower 38 may be located downstream of the condenser 110 andupstream of the drum 28. An auxiliary heater 125 may lie within the airconduit 44 downstream of the condenser 110 and upstream of the drum 28and may be operably coupled to and controlled by the controller 14.

The air recirculation loop 38 may further include a spray assembly 120.The spray assembly may be a nozzle or plurality of nozzles fluidlyattached to a pump (not shown) and may include a pressurizer (notshown). The nozzles may include atomizers for introducing atomizedliquid into the recirculating air. Atomized liquid generally refers todroplets, a mist or a fine spray. Droplet size is often dictated bypressure, specific gravity, viscosity and other physical features incombination with the flow rate of the air and the liquid itself. Airflow influences the homogeneous distribution of the atomized liquid inthe air. By way of example, an atomizer may break up liquid intodroplets having an average size of approximately 160 microns at a 20 psiwater flow rate, though the scope of the present disclosure is notlimited to these particular droplet sizes and pressure. By way ofanother example, an atomizer may break up liquid into droplets of anaverage size that is able to be homogenously suspended in moving air atflow velocities of 140-160 CFM, though the scope of the presentdisclosure is not limited to these particular droplet sizes or flowvelocities. The spray nozzles may be fixed or rotatable. Moreover, thenumber of nozzles may vary, as well as the height and positioning ofeach nozzle. Additionally, the shape, size, angle, arrangement andnumber of nozzles may vary as alternative arrangements may provide amore concentrated spray zone. For example, not only can the assembly beconfigured to provide water flow to a particular area, but the waterflow may also be configured to have more speed or more volume per area.One example would be to use a nozzle or plurality of nozzles with a fanspray for coverage of the heat exchanger coils such as a BETE 05 120Water Curtain, a BETE 08 120 Water Curtain, or a BEX Air Wisk AirCurtain, however, the scope of the present disclosure is not limited tothese particular nozzles or spray patterns. The spray assembly 120 maybe disposed in or adjacent to the airflow path and may be placedanywhere along the airflow path including inside the evaporator 105 orcondenser 110.

FIG. 2 illustrates spray assemblies, 120 a and 120 b, at two exemplaryspray assembly locations. In one embodiment, the spray assembly nozzle120 a is provided upstream of the evaporator 105 and configured to sprayliquid toward or on to the evaporator 105. In this embodiment, sprayassembly nozzle 120 a may be used as a water wash system for the heatexchanger to spray off, or clean, the evaporator 105 coils toperiodically rinse away some or all the lint and debris that mayaccumulate on the evaporator coils from the recirculating air. While thespray assembly nozzle 120 a is activated during a water wash process,the blower 58 may be activated to move the air and atomized liquidthrough the condenser 110, where it is heated, and into the drum 28,providing a steam or refresh cycle. Steam can generally refer to waterin the vapor phase, and/or hot moist air with a mist of water that mayvisually appear like steam.

In conventional heat exchanger washing processes, the airflow is turnedoff during a heat exchanger rinsing process. In this embodiment, if thewater wash system is at a high enough pressure and water flow velocityis adequate for a steam system, the airflow may be turned on during theheat exchanger wash process to provide air laden with water to thetreatment chamber for steam or refresh cycles. In the prior art, for adryer to have a water wash system for the heat exchanger as well asproviding a separate steam cycle, multiple water systems were requiredinside the dryer. Multiple water systems inside a dryer amount to extracosts and parts associated with the dryer. Utilization of a water washsystem for a heat exchanger that also provides for steam or refreshcycles as described herein has the advantage of eliminating the need fora water spray nozzle inside of the drum and the associated plumbing forthe separate steam generating system, resulting in cost savings andincreased appliance capacity.

In another embodiment, the spray assembly nozzle 120 b is providedupstream of the condenser 110 and configured to spray on or toward thecondenser 110. In this embodiment, when the spray assembly 120 b isactivated, the blower 58 may be activated to move the air and atomizedliquid through the condenser 110, where it is heated, and into the drum28, providing a steam or refresh cycle.

In one embodiment, the water is provided to the spray assembly 120 froma household supply. In another embodiment, the water is provided to thespray assembly 120 from the condensate reservoir 62. Liquid condensatemay be drawn from the condensate reservoir 62 under the evaporator 105and sprayed by the spray assembly 120 into the recirculation loop. In afurther embodiment, the water is provided to the spray assembly 120 fromboth the condensate reservoir 62 and a household supply.

The spray assembly 120 may be at any location in the air recirculationloop such that atomized liquid is introduced into the air recirculationloop 38 prior to the heated air entering the drum 28.

In any embodiment, the air recirculation loop 38 may include anauxiliary heater 125 which may be optionally activated if additionalheat is required.

FIG. 3 is a schematic view of the controller 14 coupled to the variouscomponents of the dryer 10. The controller 14 may be communicablycoupled to components of the clothes dryer 10 such as the auxiliaryheater 125, blower 58, thermistor 47, thermostat 48, thermal fuse 49,thermistor 51, moisture sensor 50, motor 54, compressor 112, sprayassembly 120, to either control these components and/or receive theirinput for use in controlling the components. The controller 14 is alsooperably coupled to the user interface 16 to receive input from the userthrough the user interface 16 for the implementation of the drying cycleand provide the user with information regarding the drying cycle.

The user interface 16 enables the user to input commands to a controller14 and receive information about a treatment cycle from components inthe clothes dryer 10 or via input by the user through the user interface16. The user may enter many different types of information, including,without limitation, cycle selection and cycle parameters, such as cycleoptions. Any suitable cycle may be used. Non-limiting examples include,Casual, Delicate, Super Delicate, Heavy Duty, Normal Dry, Damp Dry,Sanitize, Quick Dry, Timed Dry, and Jeans. By way of example, a Refreshcycle may be singly selected or as part of a treatment cycle by the userthrough the user interface 16 for dry laundry. The Refresh cycle may usewater from a household supply to generate steam and may also heat torelax wrinkles and reduce odor from dry clothes. By way of anotherexample, a dewrinkle cycle may be singly selected or as part of atreatment cycle by the user through the user interface 16 for wetlaundry. The dewrinkle cycle may use water from the condensate reservoir62 or water from a household supply, or both, to prevent wrinkles byperiodically tumbling the laundry and adding steam to the drum 28 at theend of a drying cycle. The scope of the present disclosure is notlimited to the exemplary treatment cycles herein.

The controller 14 may implement a treatment cycle selected by the useraccording to any options selected by the user and provide relatedinformation to the user. The controller 14 may also comprise a centralprocessing unit (CPU) 66 and an associated memory 68 where varioustreatment cycles and associated data, such as look-up tables, may bestored. One or more software applications, such as an arrangement ofexecutable commands/instructions may be stored in the memory andexecuted by the CPU 66 to implement the one or more treatment cycles.

In general, the controller 14 will effect a cycle of operation to effecta treating of the laundry in the treating chamber 34, which may or maynot include drying. The controller 14 may actuate the blower 58 to moveair in the air conduit 44 through the rear of the drum 28 to treatingchamber 34 when air flow is needed for a selected treating cycle. As anoption, if additional heat is needed, the controller 14 may activateauxiliary heater 125 to heat the air flow 59 as it passes over auxiliaryheater 125, with the heated air 59 being supplied to the treatingchamber 34. The thermistor 47 may sense the temperature of the inlet airthat passes through the air conduit 44 and send to the controller 14 asignal indicative of the sensed temperature. The heated air 59 may be incontact with a laundry load 36 as it passes through the treating chamber34 on its way to the air conduit 44 to effect a moisture removal of thelaundry. The heated air 59 may exit the treating chamber 34, and flowinto the air conduit 44 through the blower 58 and into the heatexchanger of the heat pump system 100 of heat pump clothes dryer 10. Thecontroller 14 may activate the compressor 112 of the heat pump system100. The moist hot recirculating air 59 may flow through the evaporator105 of the heat pump system 100 where the refrigerant in the expansiontube 116 effects cooling of the recirculating air 59 to condense themoisture present in the air. The condensate from the cooledrecirculating air 59 may be collected in the condensate reservoir 62associated under the evaporator 105. The cooled recirculating air 59 mayflow from the evaporator 105 into the condenser 110 where therefrigerant in the expansion tube 116 effects heating of therecirculating air. The recirculating air 59 may flow from the heat pumpsystem 100 through the air conduit 44 and into the auxiliary heater 125to complete one cycle of recirculating air.

The controller 14 continues the cycle of operation until completed. Ifthe cycle of operation includes drying, the controller 14 determineswhen the laundry is dry. The determination of a “dry” load may be madein different ways, but is often based on the moisture content of thelaundry, which is typically set by the user based on the selected cycle,an option to the selected cycle, or a user-defined preference.

A refresh or dewrinkle cycle may be provided to the treating chamber 34as actuated by the controller 14 via input by the user through the userinterface 16, or via stored treatment cycles in a central processingunit (CPU) 66 and an associated memory 68. In one embodiment, thecontroller 14 may activate spray assembly 120. Spray assembly nozzle 120a is provided upstream of the evaporator 105 and may introduce atomizedliquid onto or toward the evaporator 105. The atomized liquid and cooledrecirculating air then pass through the condenser 110. The condenser 110heats the atomized liquid and air to a temperature sufficient tohomogenously suspend the droplets in the air The blower 58 may draw therecirculated air containing atomized liquid into the treating chamber 34to effect the dewrinkle cycle. In this embodiment, spray assembly nozzle120 a may introduce atomized liquid to spray off, or clean, theevaporator 105 coils to rinse away some or all the lint and debris thatmay accumulate on the evaporator coils from the recirculating air priorto the atomized liquid and cooled recirculating air passing through thecondenser.

In another embodiment, the spray assembly nozzle 120 b may introduceatomized liquid into the recirculation loop upstream of the condenser110. The heat from the condenser 105 heats the atomized liquid and air.The blower 58 may draw the recirculated air containing atomized liquidinto the treating chamber 34 to effect a steam/refresh cycle.

In any embodiment, the controller 14 may activate the auxiliary heater125. The thermistor 47 may sense the temperature of the inlet air thatpasses through the air conduit 44 and send to the controller 14 a signalindicative of the sensed temperature. If the auxiliary heater 125 isturned on, the recirculated air and atomized liquid will be furtherheated prior to entering the treating chamber 34. The heater may emit anamount of heat to maintain the atomized liquid in homogenously suspendeddroplets in the air prior to introduction to the treating chamber 34 toeffect a steam or refresh cycle.

FIG. 4 is a flow-chart depicting a method of operating a laundrytreating appliance with a steam cycle according to an embodiment of theinvention. The sequence of steps depicted in FIG. 4 is for illustrativepurposes only, and is not meant to limit the method in any way as it isunderstood that the steps may proceed in a different logical order,additional or intervening steps may be included, or described steps maybe divided into multiple steps, without detracting from the invention.The method may be incorporated into a cycle of operation for the clothesdryer 10, such as prior to or as part of any phase of the treatmentcycle. The method may also be a stand-alone cycle.

The method 400 may begin at 402 by starting a drying cycle. It isassumed that the drying cycle may be implemented with laundry inside thetreating chamber 34. At 404, the blower 58 may recirculate air throughthe recirculation loop 38. At 406, atomized liquid may be introducedinto the air recirculation loop 38 upstream of the heat source by sprayassembly 120. At 406, the blower 58 may move the air to the heat source.The heat source may heat the air and atomized liquid. At 408 is anoptional step of the air and atomized liquid passing through theauxiliary heater 125. At 410 is an additional optional step to maintainthe atomized liquid homogenously suspended in the air prior tointroduction to the drum 28. At 412, heated air and atomized liquidenter drum.

It will be understood that the invention is not limited to use with aheat pump dryer. Other types of dryers where process air is heated priorto flowing into the treatment chamber also allow for spraying atomizedliquid into an air conduit upstream of the heat source so that processair laden with atomized liquid is heated prior to the process airentering the drum for the use in a steam/refresh cycle.

By way of example, in open loop heat pump dryer systems, although theexhaust is vented to the outside, the heat source for the process air isassociated in the air conduit to allow for spraying atomized liquidupstream of the heat source prior to introduction into the drum toeffect a steam/refresh cycle. And as explained above the atomized liquidcan be introduced into the air conduit anywhere, preferably upstream ofthe heat source, including at the condenser or the evaporator.

By way of another example, in condenser dryer systems, humidity isremoved by using two separate air flows. Air recirculates inside themachine and is heated by a heat source. The heated process air passesthrough the damp clothes where it picks up moisture. Moisture laden airpasses through the condenser in one direction, while the room air passesthrough the condenser in the other direction. The moisture in theprocess air condenses into water which is then pumped to the water tankor out through the drain hose. In condenser dryer systems, both open andclosed process air loop types, the heat source for the process air isassociated in the air conduit to allow for spraying atomized liquidupstream of the heat source prior to introduction into the drum toeffect a steam/refresh cycle.

By further example, a variable recirculation loop dryer system utilizesa valve system to form a closed recirculation loop for the process airuntil the process air reaches a programmed level of humidity before thevalves open and the process air is directed to outside venting. Invariable recirculation loop dryer systems, if the heat source for theprocess air is associated in the air conduit to allow for sprayingatomized liquid upstream of the heat source prior to introduction intothe drum to effect a steam/refresh cycle, the invention may bepracticed.

While the invention has been specifically described in connection withcertain specific embodiments thereof, it is to be understood that thisis by way of illustration and not of limitation, and the scope of theappended claims should be construed as broadly as the prior art willpermit. It should also be noted that all elements of all of the claimsmay be combined with each other in any possible combination, even if thecombinations have not been expressly claimed.

What is claimed is:
 1. A method of operating a laundry treatingappliance having a drum, an air conduit fluidly coupled to the drum, anda heat source associated with the air conduit, the method comprising:moving air through the air conduit to the drum; heating the moving airby operating the heat source; and introducing atomized liquid into theair conduit upstream of the heat source; wherein heat from the heatsource heats the atomized liquid before the air and the atomized liquidreaches the drum.
 2. The method of claim 1 wherein the introducingatomized liquid comprises spraying atomized liquid into the air conduit.3. The method of claim 2 wherein the spraying atomized liquid into theair conduit further comprises spraying the atomized liquid directly ontoa condenser.
 4. The method of claim 3 further comprising heating theatomized liquid downstream of a condenser.
 5. The method of claim 4wherein the heating the atomized liquid downstream of the condenser issufficient to maintain droplets in the air homogenously suspended. 6.The method of claim 4 wherein the heating the atomized liquid comprisesactivating a heating element in the air conduit.
 7. The method of claim4 wherein the atomized liquid is delivered at a pressure of about 20PSI.
 8. The method of claim 4 wherein introducing atomized liquidcomprises drawing liquid condensate from a condensate reservoir andintroducing the liquid condensate in atomized form into the air conduit.9. The method of claim 1 wherein introducing atomized liquid comprisesintroducing atomized liquid directly onto a condenser.
 10. The method ofclaim 8 wherein heating the recirculated air by operating the condensercomprises operating the condenser at a temperature sufficient tomaintain droplets in the air homogenously suspended.
 11. The method ofclaim 1 further comprising heating the atomized liquid downstream of acondenser.
 12. The method of claim 11 wherein the heating the atomizedliquid downstream of the condenser is sufficient to maintain droplets inthe air homogenously suspended.
 13. The method of claim 1 wherein theatomized liquid is delivered at a pressure of about 20 PSI.
 14. Alaundry treating appliance comprising: a drum defining a treatingchamber; an air conduit fluidly coupled to the treating chamber; ablower for forcing air through the air conduit; a heat source associatedwith the air conduit; and an atomizer fluidly coupled to the air conduitupstream of the heat source; wherein the atomizer is configured tointroduce atomized liquid into the air conduit.
 15. The laundry treatingappliance of claim 14 wherein the atomizer is upstream of a condenser.16. The laundry treating appliance of claim 15 wherein the atomizeremits the atomized liquid directly onto the condenser.
 17. The laundrytreating appliance of claim 14 wherein the atomizer emits dropletshomogenously suspended in the air.
 18. The laundry treating appliance ofclaim 14 further comprising a condensate reservoir associated with anevaporator and wherein the atomizer is fluidly coupled to the condensatereservoir.
 19. The laundry treating appliance of claim 15 furthercomprising an auxiliary heater located downstream of the condenser andupstream of the drum.
 20. The laundry treating appliance of claim 19wherein the auxiliary heater maintains droplets in the air homogenouslysuspended.